PORTION OF THE COSMOS. THE PLANETS. 335 



reasonings which have excited apprehensions, in respect to 

 the position of the apsides, the form of the planetary ellip- 

 tical orbits (according as they approximate to a circle on the 

 one hand, or to a comet-like degree of excentricity on the 

 other), the inclination of the axes of the planets, the varia- 

 tion of the obliquity of the Ecliptic, or the influence of the 

 precession of the equinoxes on the length of the year, also 

 afford, when carried to a higher degree of analytical deve- 

 lopment, cosmical grounds which counterbalance such appre- 

 hensions. The major axes and the masses are constant. 

 Periodical return prevents the indefinite accretion of parti- 

 cular perturbations. The excentricities of the two greatest 

 planets, Jupiter and Saturn, besides being in themselves 

 very moderate in amount, undergo, by reason of a reci- 

 procal and compensating influence, alternate increase and 

 decrease, which are restricted within known and determinate 

 and generally narrow limits. 



By the alteration in the position of the line of the apsides 

 ( 535 ), the point at which the Earth is nearest to the Sun 

 tends gradually to change towards the opposite period of 

 the year. If at present the perihelion falls in the beginning 

 of January, and the aphelion six months later, or in the 

 beginning of July, the progressive change of position, or 

 turning movement, of the line of the apsides or major axis 

 of the Earth's orbit, may cause the aphelion, or maximum 

 distance of the Earth from the Sun, to fall in those months 

 which form the winter of the northern hemisphere, and the 

 periheJion, or minimum distance, in our summer; so that 

 in January the Earth would be 700000 German, or 2800000 

 English, geographical miles (about -^-th of the mean distance 

 between the two bodies) farther from the Sun than in July, 



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